Rotary pressure-motor.



P. T. COFFIELD., ROTARY PRESSURE MOTOR.

APPLICATION FILED MAB.26,1908.

Patented 001;. 27,1 1908.

UNITED STATES PATENT OFFICE.

ROTARY PRESSURE-MOTOR.

Specification of Letters Patent.

Patented Oct. 27, 1908.

' Application filed March 26, 1908. Serial No. 423,378.

- of Ohio, have invented certain new and useful Improvements in Rotary Pressure- Motors; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to improvements in rotary pressure motors adapted to be driven by water pressure from a hydrant or faucet.

The primary object of the invention is to provide a motor of the above type that the water will be controlled and prevented from escaping from the motor until it has exerted its full pressure on one or the other of the pistons. Two pistons are employed upon a common shaft and located substantially in alinement with each other so that the fluid pressure is exerted against one of said pistons at a time to impart a continuous rotation to the shaft.

It is essential that one of the pistons must pass one of the valves at a time, and before it can pass a valve, there must be a communication either through or around the valve to equalize the pressures on both sides thereof, in order that the valve may be raised from its position by the approaching piston without having to contend with the pressure against said valve from opposite directions. A'pair of valves are located on one side of the axis of the piston shaft, the valve space on one side of the motor being thus essentially less than the driving space on the other side of the motor. The arrangements of the valves and the pistons are essentially the important features of the motor, as thereby the fluid is so controlled that its full pressure is exerted. upon the rotating pistons before any escape thereofthrough the exhaust can take place.

With these fundamental principles in view, I will now proceed to give a more detailed description of the invention in connection with the accompanying drawings, of which Figure 1, is a longitudinal section through the motor on the line b I) of Fig. 2. Fig. 2, is a section on the line a a of Fig. 1.

In the following description, similar reference characters indicate corresponding parts.

The motor casing 1 is enlarged on one side 2 to provide space for the drivers or valves 7, of which there are two, and to permit the pistons 10, of which there are also two, to pass said valves. The casing on one side has an integral head 3 provided with a stuffing box through which the shaft 6 passes, and on the other side said motor casing is provided with a detachable head 4 provided with a stufling box through which the shaft passes. The

- shaft is extended on both sides of the motor in order that it may be connected to transmit the power in the reverse direction. Each of the heads 3 and 4 are provided with valve seats 11 upon which the ends of the drivers or valves seat when. the inner longitudinal edges of said valves engage the enlarged portion 5 of the motor shaft.

It will be observed. that the valves are lo cated on one side of the axis of the motor shaft, and that the space B on that side of the motor is more contracted or of less area than the space A on the other side of the motor; this is essentially the case because the driving space A should be greater than the valve space B. Each of the valves is hinged upon a pin 8 which is supported in the heads of the motor and surrounding which are coil springs 13 which exert an inward pressure on the drivers or valves to maintain them upon their seats until lifted by the rotating pistons 10 10. The enlarged portion of the piston is provided with escape ports 9 9 which are designed to relieve the pressure exerted against the drivers or valves in the valve chamber B and to thereby decrease the resistance against said. valves when the pistons engage them to raise said valves from their seats, in the continued rotation of said. pistons. It will be understood that the pressures at certain periods are substantially equal in the driving and valve chambers or spaces A B, therefore, it is desirable to decrease the resistance in the valve chamber B when the pistons arrive at said valves; the escape ports 9 9 are arranged at such points that said ports communicate with the valve space B just in advance of each piston, and that there is therefore established a communication from the valve space or chamber B.

Instead of the escape ports 9 9, other means may be employed for relieving the pressure of the fluid in the chamber B such means may comprise an individual puppet valve 14 which is mounted in each of the drivers or valves 7. These puppet valves are engaged by each of the pistons 10 10 and are lifted from their seats to establish a communication between the valve chamber and the exhaust in one instance, and between the inlet and valve chamber in the other in stance. This engagement between the istons and the puppet valves takes p ace shortly before the pistons engage the drivers or valves 7 to lift them from their seats.

The action of the motor is shown in Fig. 2 where the course of the fluid in and out is in dicated by the arrows. When the piston 1.0 nearest the inlet arrives at the position indicated by the dotted line 15, the fluid pressure is exerted against said piston and is trapped in the driving chamber A between said piston and the valve or driver 7 in chamber B. The piston approaching the outlet side of the mo tor lifts the driver or valve on that side and permits the valve chamber B to exhaust. As before stated, the pressure in said cham ber is first reduced through one or the other of the ports 9 or the puppet valves 14.

It will be understood that when the piston nearest the inlet arrives at the dotted line 15 and thus seals the space between the two pistons or in chamber A, the fluid betweensaid pistons is dead; this being the case, it is desirable to cause a discharge of said dead fluid while the driven piston is making its cycle of movement. This is .done by establishing a clearance as indicated at 12 in the head of the motor between the pistons and the abutment forming the valve seat and through which the water escapes to the exhaust port from in front of the advancing or driven piston after that piston which is nearer the outlet arrives at the valve or driver in that side of the motor.

I claim:

1. In a rotary pressure motor, a suitable motor casing, two pistons located opposite each other on a rotating shaft, and a pair of drivers or valves located on one side of the axis of the piston shaft, and means enabling the pressures on both sides of the valves to be equalized in order that each valve may be raised from its seat by the approaching piston, said piston thus being relieved from moving the valve against opposing pressure.

2. In a rotary pressure motor, two pistons mounted upon a rotating shaft, two drivers or valves mounted in pockets in the motor casing adjacent to the inlet and outlet to and from the motor, and means to relieve the pressure in front of the valves before the approaching piston engages said valve.

3. In a rotary pressure motor, a suitable casing, two pistons mounted upon a rotating shaft within said casing, two drivers or valves mounted respectively adjacent to the inlet and outlet to and from the motor, one

of said valves serving to trap the motive fluid between it and a piston while said piston is passing the other valve, and means for equalizing the pressures upon both sides of a valve before said valve is raised by the approaching piston.

4. In a rotary pressure motor, a suitable casing having one inlet port and one outlet port, two pistons mounted upon a rotating shaft, two valves mounted in pockets in said casing on one side of the axis of the piston shaft, one of saidivalves being adapted to trap the motive fluid while one of the pistons is passing the other valve.

5. In a rotary pressure motor, a suitable casing having inlet and outlet ports, a plurality of pistons mounted on a rotating shaft within said casing, valves mounted in pockets in said casing, one of said valves being adapted to trap the motive fluid between it and the driven piston while the other piston is passing the other valve, and means for equalizing the pressures on both sides of the valves before each valve is raised by the approaching piston.

6. In a rotary pressure motor, a suitable casing having one inlet port and one outlet port, two pistons mounted upon a rotating shaft in said casing, two drivers or valves mounted in said casing on one side of a plane drawn through the axis of the motor and adapted to seal the inlet from the exhaust to obtain a maximum pressure of the motive fluid against the driven piston.

7 In a rotary pressure motor, a suitable casing having inlet and outlet ports, two pistons mounted upon opposite sides of a rotating shaft, two valves mounted in said casing on one side of the axis of the piston shaft and adapted to seal the inlet from the outlet at all times to obtain a maximum driving pressure against the driven piston, and means for equalizing the pressures on both sides of the valves before a piston engages a valve to raise the same.

8. In a rotary pressure motor, a casing having inlet and outlet ports, two pistons mounted upon a rotating shaft within said casing, two valves mounted in pockets in said casing, one or the other of said valves adapted to seal the motive fluid between the inlet and the exhaust while one or the other of the pistons is passing the other valve, said pistons being adapted to raise said valves, and means whereby the pressures are equalized on both sides of said valves before a valve is raised by an approaching piston.

In testimony whereof I aflix my signature, in presence of two witnesses.

' PETER T. COFFIELD.

WVitnesses:

C. M. THEOBOLD, MATTHEW SIEBLER. 

